1. Field of the Invention
The subject invention relates to a system for controlling brake motors or steering motors on a vehicle. More particularly, this invention relates to a system for redundantly controlling brake motors and steering motors on a vehicle having a brake by wire or drive by wire system.
2. Description of the Prior Art
Brake by wire and drive by wire systems are known in the prior art whereby one can control the steering and braking functions of a vehicle using a control device, such as a steering wheel and brake pedal or joystick. Typically, these systems have more than one communication channel for communicating signals from the control device to the steering and braking motors such that, when that communication channel experiences an error, the entire system is not inoperable.
Control systems with redundant communications networks are typically accomplished using two different families of device controllers, wherein each family of device controllers operates independently on two separate networks. These redundant systems require a significant amount of hardware, which are difficult and expensive to package in a vehicle with a drive by wire or brake by wire system.
It is desirable to provide redundancy in a brake by wire or drive by wire system.
The invention provides a safety redundant drive by wire system comprising a plurality of brake motors disposed in corners of a vehicle to which control signals may be communicated. A plurality of sensors are disposed in the system, such that at least one sensor is coupled to the brake motor for sensing a parameter of the brake motor and responsively generating a sensor signal. A device controller is disposed in the corners of the vehicle and adapted to deliver control signals to a respective brake motor. Each of the device controllers includes a first and second microprocessor for communicating control signals to the brake motor associated with that device controller, all other device controllers and each other. Each device controller is adapted to receive the sensor signal and provide it to the first and second microprocessors.
The control signals are communicated over a dual redundant communication channel system having a first communication channel for communicating control signals from one device controller to all other device controllers, and a second communication channel for redundantly communicating control signals between device controllers. The first and second microprocessors control the first and second communication channels, respectively.
A plurality of hardware configurations which may be used independently or together in some combination to achieve redundant drive by wire and brake by wire systems. Accordingly, the first and second microprocessors on a device controller control the first and second communication channels, respectively, providing a redundant drive by wire and brake by wire system with minimal hardware.